I have a category that has about 6 forums. All have no public access; you need to be granted rights by being added to a certain group.

Its been running fine for a years now, but now suddenly, out of the blue, one of the forums isnt visible. I checked the Admin CP and its there, forum can be edited, moved. Its even listed in the database, but it wont show up on the main page.

I have checked perms, but being site Admin, I have access to all forums anyway.